CA1197110A - Fertilizer compositions, processes of making them, and processes of using them - Google Patents
Fertilizer compositions, processes of making them, and processes of using themInfo
- Publication number
- CA1197110A CA1197110A CA000411552A CA411552A CA1197110A CA 1197110 A CA1197110 A CA 1197110A CA 000411552 A CA000411552 A CA 000411552A CA 411552 A CA411552 A CA 411552A CA 1197110 A CA1197110 A CA 1197110A
- Authority
- CA
- Canada
- Prior art keywords
- granules
- soil
- particles
- melamine
- urea
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Fertilizers (AREA)
Abstract
ABSTRACT
This invention relates to a fertilizer product in granular form, to processes for making and using it. The granules have strength, sizes and weights suitable for mechanical dispensing and application to the soil. These granules combine a particulate nitrogen source such as melamine with a binder such as urea.
This invention relates to a fertilizer product in granular form, to processes for making and using it. The granules have strength, sizes and weights suitable for mechanical dispensing and application to the soil. These granules combine a particulate nitrogen source such as melamine with a binder such as urea.
Description
~9~
FERTILIZER COMPOSITIONS, PROCESSES OF MAKING THEM
AND PROCESSES OF USING THEM
BACKGROUND OF THE INVENTION
This inventiDn relates to a new fertilizer product in composite granular form, to a process for making it, and to a process for using ie . More particularly, the invention relates to a granular fertilizer product in which the granules have strength, sLzes, and weights suitable for mechanical dispensing and application to and into the soil. These new fertilizer granules provide a novel combination of fine particles: a particulate nitrogen source such as melamine together with a binder such as urea suitable for binding the particulate nitrogen source into granular form.
~ mmonia, am~onium nitrate and urea are among the most commonly used sources of nitrogen but all of these nitrogen fertili7er materials are readily soluble in water. They are therefore sub~ect to leaching, and their use results in a rapid release of their nitrogen. Since this necessitates repeated applications for sustained growth, Dr one application with higher leaching losses, there have been many developments relating to slow rel~ase nitrogen fertilizer materials. Generally such materials sacrifice nitrogen content for some degree of control over nitrogen availability.
M~l~m; ne and its hydrolysis products, -1~nP~ am~elide, and cyanuric acid, have been considered as potential sources of nitrogen for incorporation in fertilizer compositions or for utilization as nitrogen sources per se. Melamine has a nitrogen content of 66.6~. If it could be used as a fertilizer material, it would provide a good deal of nitrogen per unit weight applied.
However, at present it is more sY~pensive than urea. ~oreoverr commercially produced ~ mlne is available only as a fine crystalline powder. It is manufactured in the form of very fine crystals because small size particles are required for the present commercial end markets for r~l~mine, such as, for e~ample, the 7~
production of melamine-formaldehyde resins and the production of fire retardant paints.
A typical screen analysis for one comnercially available melamine, conducted with United States Standard Sieve screens, is as follows:
Percent Screen Analysis Retained 40 Mesh 0-0.1 40-50 Mesh 0-0.1 50-60 Mesh 0-0.3 60-80 Mesh 0.5-5.0 80--100 Mesh 1.0-5,0 100-200 Mesh 13-30 200-325 Mesh 13-30 Thru 325 Mesh 40-60 The commercially-produced small melamine crystals are desired by the resin producers because the small crystals dissolve more readily, and any larger particles, if present, would tend to require a longer processing time; therefore, the larger particles are less desirable. In the fire retardant paint market, the melamine crystals are dispersed in the paint, where the currently used fine particle sizes produce a smoother texture in the dried paint than would larger particles.
The fine particle sizes of the commercially available melamine products make melamine a product that is not very attractive for agricultural applications. Moreover, the fine particle sizes of commercial melamine as currently produced, make it impractical to use a fertilizer material. The fine particles, if applied to the surface of the ground~ would be blown away by even milt winds. If applied by air, as from an airplane or helicopter, drifting wou~d be a serious problem ~nd would cause uneven application. If applied through mechanical applicators, the fine particles would tend to form bridges and thus would plug transfer and dispensing lines. These difficultie~ in handling the 7~0 commercially available melamine solids would make any large scale agricultural application impractical.
SUMMARY OF THE INVENTION
In one of its aspects, this invention resides in a fertili~er product in granule form. The fertilizer granules have strength, sizes, and weights that are suitable for dispensing mech~nic~lly for application to and into the soil. The preferred size range is from about 1 millimeter to about 10 millimoters, and the most preferred size range is from 3 ~m. to 5 mm.
These fertilizer granules comprise a particulate nitrogen source and a binder. The nitrogen source is characterized by fine particle sizes not above about 10 mesh, by poor solubility in pH 7 water at 20C, and by slow conversion in the soil to a form in which it is useful to plant life growing in the soil. The nitrogen source is selected from the group of materials consisting of melamine, ammeline, ammelide, cyanuric acid, mixtures thereof, their inorganic salts, their organic salts and mixtures thereof.
The binder is present in an amount at least sufficient to bind together the fine crystals or powder particles of the nitrogen source, to form granules having the desired strength. It is preferably a readily soluble material that, after distribution of the granules in the soil, releases the nitrogen source particles to permit the action of water and microorganisms on the particles.
The binder is selected to be compatible ~ith the soil, and any residue of the binder should be either inert, biodegradable, soil condltioning or have plant nutrient value.
The binder is selected from the group of materials consisting of urea, ammon~um sulfate, potassium sulfate, ammonium nltrate, ammonium phosphata, potassium nitrate, potassium chioride, ammonium chloride, potassium dihydrogen phosphate, lignin sulfonate, urea formaldehyde resin, -l~m~nP formaldehyde resin, starch, latex and mixtures thereof.
In a preferred embodiment the granules comprise up to 80 parts by weight of the particulate nitrogen source and at least 20 parts by weight binder.
In a more preferred embodiment the granules comprise from 60 to 80 parts by weight melamine and from 20 to 40 parts by weight urea. In another preferred embodiment the granules comprise from 67 eO 80 parts by weight melamine and from 20 to 33 parts urea. In a most preferred embodiment the granules comprise about 67 parts by weight melamine and about 33 parts by weight urea.
In another aspect this invention resides in a granule prepared by a process having an annealing step to provide enhanced strength to the granule and adapting them for use as a source of nitrogen for fertilizing applications. This process involves mixing a particulate nitrogen source selected from the group of materials listed above with an effective amount of a binder suitable for binding the nitrogen source particles into granules having sizes and weights suitable for mechanical application. The mixture is then contacted with a spray of water or an aqueous solution of the binder. The moistened mixture is agglomerated, dried and annealed. In a preferred embodiment the process requires a dryin~ temperature of less than g30C and an ~nnP~ temperature between 135C and 149C. In a most preferred embodiment this granule is prepared from a mi~ture of from 50 to 80 parts by welght mPl~m~ne and from 50 to 20 parts by weight urea.
In another aspect of thls invention is a fertilizer in prill form. This prill is prepared by mixing an effective amount o~ a molten binder selected from the group of bi~der materials listed above with fine powder particles of a particulate nitrogen source selected from the group listed above. Drops of this mixture are then chilled to form prills. In a preferred embodiment this prill comprises from 40 ~to 65 parts by weight melamine as the particulate nitrogen source and from 35 to 60 parts by weight urea binder. In another preferred embodiment this prill comprises 50 to 60 parts by weight melamine and 40 to 50 parts by weight urea.
In another embodlment this invent~lon involves a process of preparing a fertilizer product in granular for~ adapted ~or use as a source of nitrogen for fertilizlng applications. This process involves mixing a particulate nitrogen source selected from the group listed above and an effective amount of a binder selected from the group listed above. The process involves contacting the mixture with a spray of water or an aqueous solution of the binder, agglo~erating the moistened mixture to form agglo~era~es and drying the agglomerates. The agglomerates are screened to produce product agglomerates havi~g sizes in th~ range of 1 milli~eter to 10 milli~eters, preferably. Over-sized particles can be crushed to size, and fines can be recycled.
In another preferred embodiment the process requires mixing from 50 to 80 parts by weight melamine with from 50 to 20 parts by weight urea binder. In a most preferred embodiment this process involves mixing about 67 parts by weight melamine with about 33 parts by weight urea.
In another embodiment this invention involves a process for preparing a granular agglomerate adapted for use as a source of nitrogen for fertilizing applications which involves an annealing step following and in addition to the mixing, contacting, agglomerating and drying steps of the process descrlbed above. In a preferred embodiment this invention involves drying the agglomerates at a temperature less than 93~C and annealing the dried agglomerates at a temperature between 135C and 149C. In another preferred embodiment this process comprises mixing from 50 to 80 parts by weight ~l~ne and 50 to 20 parts by weight urea.
As a rule, crush strengths of 1000 grams or greater are attained where the annealing step of heating to 135C to 149C ie carried out on the granules made from melamine and urea.
In another aspect this invention is a process of fer~
tili~ing crops comprising dispensing to the soil a granular product comprising a particulate nitrogen source selected from the group listed above and an effective amount of a b;nder selected from the --S
r. ~
group of binders listed above. In a preferred embodiment this process involves dispensing to the soil a granular product comprising up to 80 parts by weight of the particulate nitrogen source and at lease 20 parts by weight binder. In a most preferred embodiment this process involves dispensing a granular product comprising up to ~0 parts by weight melamine and at least 20 parts by weight urea.
In another aspect this invention is a process of fer-tilizing crops which involves dispensing to the soil a granular product having strength, size and weight suitable for mechanical dispensing and application formed by mixing an effective amount of a binder selected fro~ the group of binders listed above and a particulate nitrogen source selected ~rom the group of nitrogen sources listed above. After the mixing step the process involves contacting the mixture with a spray of water or an aqueous solution of binder, agglomerating the moistened mixture to for~
agglomerates, drying the agglomerates and annealing the dried agglomerates. In a preferred embodiment this process comprises mixing melamine as the particulate nitrogen source with a urea binder. In another preferred embodiment this process involves fertilizing a crop of corn, potatoes or rice.
In these processes of fertilizing crops, the total rate of application is such as to insert enough total long term er-tilizer nitrogen for an entire growing season. A primary ad-vantage of this process, and of the use of the composite granular fertilizer prepared in accordance with the invention, is that the rate of application of the fe~tilizer generally is less ~han one-half of that needed to achieve comparable results when ammonium sulfate is employed as the sole source of nitrogen and is applied as a solution through an irrigation sprinkler system.
In another aspect this lnvention is a process of fur-nishing a slow release source of fertilizer nitrogen to field soil as a nutrient source for a crop by inserting and distributing in the soil in the root ZQne in particulate form a fertilizer nitrogen source that ls characterized by poo~ solubility in pH 7 water at 20C. This slow release nitrogen source may be melamine, ~l~nP~
a~melide, cyanuric acid, their organic or inorganic salts or mixtures thereof. After applying the solid form of the nitrogen source on the surface of the soil a portion of the soll is turned over to insert and distribute the fertilizer at the desired depth range throughout the soil.
In another aspect this invention is a process of applying the slow release nitrogen source described above in tlle form of a slurry of solids suspended in an effective amount of a liquid vehicle for the nitrogen source that permits application of the slow release fertili~er particles to and their distribution in the soil.
DEFINITIONS:
The term "poorly water soluble" refers to materials that dissolve in water at 20~, pH7, to the extent of 5 grams per 100 grams, or less; that is, materials that form solutions of 5% or less concentration. The term l'poor solubility" in pH 7 water at 20C has the same meaning.
The term "readily water soluble" refers to materials that dissolve ln water at 20C, pH 7, to the extent of 20 grams per 100 grams or more, that is, materials that form solutions o~ 20% or greater concentration.
Based on available information, the solubilities in water at 20C, pH 7, for several materials useful in connection with this invention, in grams per 100 grams are:
Table I
Solubility Data Material ~ ~
30r~ m;nf~O.50 ne 0.008 ammelideless than 0.008 cyanuric acid 0.27 melamine nitrate 0. 85 ammonium nitrate 192 ammonium sulfate 75.4 7~
diammonium phosphate 131 (at 15) potassium acid sulfate 51.4 potassium sulfate 11.1 urea 119.3 (at 25C) DETAILED DESCRIPTION OF THE INVENTION
Fertiliæer products in accordance with the present in-vention are in granular form, with sizes in the range from about 1 mm. to 10 mm., preferably 3 mm~ to 5 mm. They are made up to have good drillability, a desirable apparent specific gravity, and to be substantially free from dusting. The granules are also made to be suitable for mechanical d~spensing and application to and into the soil using modern toolsO
Granular fertilizer products made in accordance with pre-ferred embodiments of the invention may be in the form of agglomer-ates or prills. The agglomerates may be made by any conventional technique for agglomerating fertilizer products, utilizing the poorly or slightly soluble fertilizer nitrogen sourcés of the present invention, followed by an annealing treatment to provide sufficient crush strength. Thus, the poorly or slightly soluble nitrogen source in an agolomerate is sPlected from the group consisting of melamine, ammeline, ammlelide, cyanuric acid, mixtures thereof, their inorganic salts, their organic salts, and mixtures thereof. These salts are preferably selected from the group consisting of the hydrochloride, hydroiodide, metaphosphate, nitrate, orthophosphate, orthophosphate dihydrate, polyphosphate, potassium dihydrogen phosphate, bisulfate, and sulfite, and, as well, the acetate, cyanurate, chloroacetate, formate, benzoate, fumarate, lactate, maleate, and phthala~e, and mixtures thereof.
These materials are characterized by poor or slight solubility in pH 7 water at 20C, and by slow conversion in the soil to a form in which the nitrogen is useful to plant life growin~ in the soil~
These nitrogen source materials, as ordinarily available commercially or as prepared, are in the form of very fine particles. In the case of -l~mine, for example, the co~mercially ~a7~
~vailable product typically has crystalline particles that are smaller in size than 10 mesh, U.S. Standard Sleve si~e, and generally, mostly smaller than 40 mesh. These very fine, powdery nitrogen source materials are agglomerated through the use of a binder. Generally the binder forms at least 1~ by weight of the powdery particles, preferably at least 2% by weigh~ of ~he powdery particles, and more preferably, at least 5~ by weight of the powdery particles. The blnder may be selected from a broad spectrum of materials, but preferably is selected to be compatible with the soil so that it and any residue thereof i5 either inert, biodegradab]e, soil-conditioning, or has some plant nutrient value.
The binder that is used should be sufficiently strong, upon hardening or curing, to impart to the granular agglomerates a crush strength of at least 454 grams, as determined by tests on ten agglomerates randomly selected, with sizes in the range from 3 mm.
to 4 mm., the results being averaged. Preferably, however, the crush strength is at least S80 grams, and more preferably, 908 grams or higher. A crush strength of about 45~ grams is comparable to conventional, commercial prilled urea and is adequate strength for use in most forms of commercial application, including broad cast devices, spreaders, planter shank applicators,`and for dis-pensing from airplanes and helicopters.
Among the preferred binders are those selected from the group consisting of lignin sulfonate and its salts, starch, urea, urea-formaldehyde resins, mPlAmlne-formaldehyde resins, and latices of synthetic polymeric materials. Those binders are most preerred that have plant nutrient value, as do urea, urea-for~aldehyde and melamine-formaldehyde resins.
In one preferred a~glomeration technique, the mpl~m~ne powder is combined with from 5% to 25~ by weight of powdered urea to for~ a blend. This blend is then sprayed with water or with a solution of urea, in an agglomerating de~lce such as on a rotating disc or in a rotating drum. In the case of a binder solution, the particles are coated. In the case of a water spray, the urea _g_ either goes into solution or becomes moistened and tacky, and in either state, coats the powdery melamine particles sufficiently to cause agglomeration to occur. ~he agglomerates are dried and cooled, to form hard composites having sizes pr-lmarily in the rante from about 1 mm. to about 10 mm., and preferably 3 mm. to 5 mm.
These composites have good crush strength and are substantially free from dusting.
Any of the conventional agglomerating techniques can be used. Thus, all of the binder can be applied in solution. Whe~
the binder is a material such as lignin sulfonate, urea-formaldehyde resin, or melamine-formaldehyde resin, application in the form of a solution is usually most convenient. The binder might also be a material such as a phenolic resin, applied from a solution, but such a material, while having exrellent characteris-tics as a binder, has no nutrient value to contribute and is there-fore less desirable. The same considerations apply to synthetic polymer latices.
The fertilizer particles of the invention may also be made in the form of prills. In the prilling operation, melamine powder is added to a molten binder material, preferably urea, to form a slurry of the melamine powder particles in the molten urea.
Droplets of this molten slurry are solidified by dropping them through a prillin~ tower, in the conveneional fashion. While urea is the preferred material for use in preparing prllls, because of its nitrogen content and ready solubility in water, and also because ~ mine is somewhat soluble in molten urea, other material such as sulfur could also be used, and mix~ures of materials could be used. In forming urea-bound prills, it is preferred that the prill product contain at least 33% by weight of urea. When less urea is present, it is difficult to prepare a flowable slurry. The urea content of the prill may be as high as 90~, so that the melamine content may be in the range from 10% to 67~ by weight of the prills. Preferably, the urea content is from 35% to 60% by ~7~
weight of the prills, and more preferably~ from 40~ to 50% by weight.
Whlle preferred granular products are produced by agglomera~ion and prilling, satisfactory products can be produced by other techniques, including extruding techniques, pressing and granulating, and bricquetting. For example~ ~J~m;ne powder, or a powdered melamine salt, or the like, can be combined with a urea formaldehyde resin in powder form to form a mi~ture. The mixture can be pressed at an elevated temperature to cure the resin, and the resulting product can be granulated to form particles of the desired size, or the pressed, cured mass can be converted to flake for~. Screening and recycling can be used as necessary to develop ~ranules of the deslred sizes.
Readily soluble binders such as urea and salts such as ammonium nitrate permit rapid disintegration of the binder of the Eertilizer granules in the soil, with release of the fine melamine or other fine particles. This may be desirable where the composite contains not only melamine but also a readily soluble, fast release r.itrogen fertilizer material. Where slow release is desired, then ordinarily one of the binders is employed that loses binding power more slowly in the soil, such as, for e~ample, a urea-formaldehyde resin or a -lAm;ne-formaldehyde resin.
Urea is a preferred binder for agglomerates, or for making prills, because it not only permits the production of fer-tilizer granules of sufficient size, strength, and weight, for convenient applicationl but in addition, the urea is readily soluble and adds valuable fast release nutrient material to the soil. When used with a powdered nitrogen source characterized by poor or slightly solubility and slow conversion in ehe soil to a useful form, the urea dissolves rapidly and releases the fine particles of the poorly soluble nitrogen source into the soil, for slow dissolution or biodegradation.
~ hen an agglomerate is prepared fro~ powdered r~l~m~ne and a readily water soluble binder such as urea, preferred pro-~,Jb~
portions in the dried granular product obtained are from 60% to 85 by weight of melamine and from 40~ to 15~ by weight of urea~ or more preferably, from 67% to 80% by weight of melamine and from 33%
to 20% by weight of urea. The most preferred granule comprises about 67 parts by weight melamine and about 33 parts by weight urea.
I~en an agglomerate is produced using an insoluble or only slightly soluble binder such as starch, a derivatized starch9 or a modified starch, lignin sulfonate, urea-formaldehyde, or -l~m~nP-formaldehyde, or one of the non-m1trient materials such as a phenolic resin, or a synthetic polymer in the form of a latex, a very slow release of nitrogen from the-melamine particles (or particles of other poorly soluble nitrogen source) is obtained.
For the production of an agglomerate permitting a single application per growing season, fast release nitrogen fertilizer I materials, generally an ammonium salt or urea, are advan~ageously used as the binder of the agglomerate. Examples of such salt-type binder materials are ammonium sulfate, potassium sulfate, ammonium phosphate, diammonium phosphate, the potassium phosphates, ammonium nitrate, potassium nitrate, potassium chloride, and ammonium chloride. When used as a binder material in the formation of an agglomerated composite, the proportion of such salt-type binder material may be from 15~ to 40% by weight of the agglomera~e, and preferably is from 20% to 33% by weight of the agglomerate.
In addition, other materials may be incorporated in a granular fertilizer product prepared in accordance with the in-vention. Such materials may be micronutrients such as zinc, magnesium, iron and boron.
One of the advantages of the use of granular fertilizer compositions prepared in accordance with the present invention is that the rate of application may be much lower in terms of nitrogen applied per acre than i9 true with standard fertilizer practice.
Because less of the active material is actually needed, it may be desirable, to facilitate application, in some cases9 to incorporate an inert filler. Any of the conventional filler materials may be e~ployed, such as, for example, gypsum, clay9 sand, ground se~
shells, ground dolomite, and ground limestonP.
Another important advantage of the use of granular fertilizer products in accordance with the present invention is that, because of the slow release characteristics, lt is possible to employ only a single application per growing season. In addition, after the initial application, in the case of L.el~mi~e based fertilizer products in particular, the release of nitrogen values into the soil appears to continue over two growing seasons.
Consequently, in the second and subsequent gro~ing seasons, even lower rates of application may be employed for given results, than may be used for the initial application.
Another aspect of the invention ls the unexpected and surprising finding that furnishing a majority or all of the nitrogen fertilizer requirements by a nitrogen fertilizer source in accordance with the present invention apparently leads to a more effective production of agricultural productive units per unit weight of nitrogen ~pplied, and per unit of growing area. A~
agricultural productive unit is a seed, fruit, flower, vegetable, vegetable fiber, tuber, or the like. In addition, the practice of the invention apparently leads to overall yields of plant units comparable to those obtained when following conventional, standard fertilizer praceice, with its requirement for the use of much higher nitrogen fertilizer application levels.
In broad terms, this invention may be considered, in one example, as a process for increasing the effectiveness of standard readily soluble, fast release nitrogenous fertilizers in generating productive units in agricultural crops by supplementing their action ~ith the use of a slow release, poorly or slightly soluble fertilizer nitrogen source. Thus, a combination of fro~ about 10%
to about 50% of the nitrogen in a standard readily water soluble, fast release nitrogenous fertilizer may be combined advantageously with from about 50~ to 90~ of poorly soluble materials recited above.
The agricultural crops expected to respond to treatment in accordance with the invention include substantially all crops, but particularly those where fruit is the harvested unit rather than the entire plant. Such crops include food grains, feed grains, legumes, fibers, root crops, citrus, tubers, oil bearing units including nuts, fruits and seeds, commercial vegetables, commercial melons, ~ree fruits, vine fruits, bush fruits and flowers. Exemplary food grains include wheat, rye, and rice Feed grain crops include field corn, oats, barley and sorghum. Legumes include soybeans, peanuts, beans and peas. Fiber crops include cotton, hemp and jute. Root crops include sweet potatoes and sugar beets. Citrus crops include oranges, tangerines, grapefruit~
lemons and limes. Tuber crops include potatoes. Oil crops include flax, safflower, sunflower, and castor bean. Commercial vegetable crops include lima beans, snap beans, beets, carrots, sweet corn, cucumbers, onions, green peas~ and tomatoes. Commercial melon crops include cantaloupes, honeydews and watermelon. Tree fruit crops include apples 7 peaches, pears, cherries, and plums. ~ine fruits include grapes. Bush fruits include the many different kinds of ber}ies, especially raspberries and blueberries. Tree nut crops include almonds, filberts, pecans and walnuts. These are intended to be exemplary only.
The invention will be better understood by reference to the following examples. Throughout this application and in these examples, all references to parts and percentages are by weight, and all references to temperatures are in degrees Celsius, unless expressly stated otherwise.
Examples of the Formation of Granules that are Useful in the Process of the Invention In all of the following examples, the melamine used was the commercially available product of ~ ml~e Chemicals, IncO, Donaldsonville, Louisiana. It was a fine white crystalline powder 37~L0 having a screen analysis substantially as reported above for co~mercially available melamine. It was about 99.9% pure, with specifications of a r~1ml1m moisture content of 0.1~ mllm ash of 0.01%, and a density of about 1.57 g/ml.
As is pointed out in some of the following examples, crush strengths of 454 grams or greater are preferred. More preferably crush strengths of 1362 grams or more are developed, to facilitate application. Also, the bulk density of the granules should be 40 lbs./ft3 or more. The preferred combination of bulk density, crush strength, and particle size makes }or flexibility in and ease of application. Usually crush strengths of 1000 grams or greater are attained when the annealing step of heating to 135C to 149C is carried out on the melamine urea granules.
EXAMPLE I
M~l~m;ne Agglomerates Using a Urea Binder Three batches of composite granules were made up, each containing different amounts of urea and melamine, with urea serving as the binder. These batches of agglomerated granules were made in a pan agglomerator of 9" diameter. The urea was first ground, and then blended with the melamine powder to form a homo geneous mixture. The powder mixture was fed to the pan agglomerator and sprayed with a nearly saturated solution of ure~
and water, The solution added about 7% urea to the dried agglo-merate. The remainder of the urea content was derived from the urea powder in the urea-melamine powder mixture.
Example II
Annealed M~lAmine Granules A batch of granules was prepared using 67 parts of melamine crystals and 33 parts urea. The granules were made on an 18 inch disc pelletizer. The urea was first ground, then blended with the ~ mine to form a homogeneous mixture. This mixture was fed to the pelletizer and sprayed with water. T~e granules were dried at 200F. (94C) for about 20 minutes and then were subjected to a further step of heating in a laboratory oven to 149C for 3 ~7~
minutes. After cooling, the crush strength and rate of breaking apart in water were measured. These values are reported in Table I
below.
Table I
Crush Strength Time to Disintegration (grams) in Water Example 1 600 immediate Dried Granules Example II 2400 20 to 30 seconds Annealed Granules This Example illustrates the relationship between time and temperature in the annealing step.
Example III
Annealed MPl~mine Granules Melamine granules prepared according to E~ample II were heated in separate batches at 104C, 149C, and 172C for varying times. A standard laboratory oven was used. After cooling, the crush strength was measured. The results appear in Table II. The r~;mllm crush strength at 172C appears at 6 minutes heating~ The r~imllm crush strength appears at 149C at 11 minutes heating.
Shorter drying times and annealing times will be possible in pro-duction when forced air dryers or ovens will be used in place of the laboratory oven used in these examples.
Table II
Oven Temperature Minutes Crush Strength C Heating (grams~
\
~37~
lS 1530 145~
Example IV
Melamine Agglomerated with Urea Powder; Water Spray One batch of agglomerated granules was prepared in a pa~
agglomerator as in Example 1, except that all of the urea was added as a powder, and the spray applied at the pan consisted only of water. The resulting composites contained 80% melamine and 20%
urea, and after screening to 3-4 mm., were found to have a crush strength of 953 g. using the same testing technique as in Example I.
Example V
Use of Other Binders for Agglomerating Melamine Granular agglomerates were prepared wlth a 16 inch pan agglomerator using r~lAm~ne with several different bindersO In each case, the binder, in liquid form, was sprayed on the melamine.
After drying, crush strength was deternined as in Example I. The results are reported in Table III, below.
TABLE III
Crush Strengths ObserYed Melamine Agglomerated with Different Binders Crush Strength, grams of 3-4 mm.
Binder Agglomerates Calcium lignin sulfonate1 908 7~
UCAR 368 latex 681 Melamine-formaldehyde resinl 1544 Urea-formaldehyde resin 454 Diammonium phosphate {DAP) 91 Ammonium nitrate2 150 1Applied at 30%-50% solids. The dried agglomera~es were about 5Z binder.
Substantially saturated solutions used. The dried agglo-merates were approximately 93% melamine, 7% salt.
Example VI
Melamine Agglomerated with other Fertilizer Materials Melamine, ammonium phosphate, and potassium chloride were blended together in a 70:15:15 weight ratio. The mixture was fed to a 16 inch pan agglomerator and sprayed with a 30% solids lignin sulfonate solution. The dried, screened granules had a crush strength of 1000 grams in the 3-4 mm. size range, and a binder content of 3Z.
- Example VII
Melamine in Matrix of Solidified Urea Binder Melamine and urea powder werP blended in a 63-37 ratio.
The blend was heated until a molten slurry was obtained. The slurry was then poured onto a cooling slab so as to form both a thin film and a thick film. After cooling the thin film was broken into flakes.
The thick film3 of about 4 mm. thickness, was broken into granules. The crush strength of the 3-4 mm. granules was ex-ception~lly high, at 2500 grams.
Example VIII
A Pressed ~Pl~m;~e-Urea Composite A melamine-urea blend was formed as in Example VII. This blend was then placed in a heated platen press at about 500 psi for 5 minutes, at 138C. The resulting hot composite9 in the form of a sheet about 4 mm. thick, was then removed from the press and ~18-~ ~ ~7~ ~ ~
allowed to cool. The cooled sheet was granulated, and 3 4 mm.
granules of the composite had a crush strength of 2500 grams.
Example IX
Melamine-Urea 60/40 Prills Melamine composite prills were prepared by heating 40 parts urea by weight with 60 parts ~ m;ne by weight. Heating was done in an aluminum can using electric heating tape. A slurry formed at 135C. Holes were then punched in the can bottom, allow-ing the slurry to drip. A plastic sheet spread on the ground caught the falling prills as they dropped from the fourth story level.
The largest prills did not cool before landing and smashed. However, the smaller pr~lls cooled and solidified, and were collected for strength testing. Fairly good strength results were achieved, although not measured. Crush strength would be e~pected to be similar to the granules of Example VII.
Example X
Melamine Agglomerated with a Late~ Binder 5% Union Carbide UCAR 368 Latex, 15% water, and 80%
melamine were combined into a flowabl~ slurry. A sheet of the slurry was formed and then dried. An extremely strong composite resulted which could be granulated. The dried material contained 3~ latex solids and 97% melamine. The crush strength of 3-4 mm~
granules was 2180 grams.
Example XI
Pressed Composite of ~elamine and Ure-Formaldehyde 25 grams of urea, 70 grams melamine, and 15 ml. of 27%
formaldehyde solution were mixed together and pressed at 149C and 500 psi to form a thick sheet. Crush strength of 3-4 mm. granules 3C ~as 680 grams.
Example XII
Melamine-Urea Agglomerates for Field Trials For field trials, 16,000 pounds of mPl~mine/urea com-posites were made using 4 foot diameter pan agglomerators.
Different composites were produced, at the melamine/urea ratios of 80/20, 75/25, and 67/33. Approximately 7% of the composites was provided by the urea added in the form of an aqueous binder solution, and the remaining urea was provided by powdered urea that was blended with the melamine powder prior to agglomeration.
In the foregoing examples, granular fertilizer products were prepared from commerciaLly available9 fine crystals of melamine. Similar granular fertilizer products can be prepared in substantially the same fashion from the hydrolysis products of melamine, i.e. ammeline, ammelide, and cyanuric acid, and from salts made from them and from m~l~m;ne~ Among the salts, the reaction product of nitric acid and melamine is a preferred material.
Example XIII
Corn Trials Using Melamine-Urea Agglomerates; Evaluation of Different Application Techniques Test plots totaling 40 acres of sandy to light loams and silts were treated with different amounts of melamine agglomerates to provide several different levels of applied nitrogen per acre.
MP1~mine-urea agglomerated composites were used, prepared according to Example I and having 67 parts melamine to 33 parts urea binder;
75 parts melamine to 25 parts urea binder; and 80 parts melamine to 20 parts urea binder. The composites were successfully applied using different techniques: 1) spreading with a Barber spreader; 2) spreading with a Barber spreader and plowing into the ground; 3) aerial application by airplane; 4) shanking into the ground during planting.
The results observed are summarized in Table IV below.
Table IV
Corn Trials - Effect of Application Method Number of Average ~umber Nitrogen Level Melamine/ Application Ears/100 of Ears (lbs./acre UreaTechnique Plants per Plant 140-150 75/25 (1) 155 1.55 140-150 75/25 (2) 147 1.47 1~0-150 75/25 (3) 155 1.55 150 80/20 (4) 153 1.53 0 (Control~ - 132 1.32 400 UN-32 ** 129 1.2g 400* * 145 1.45 *Standard Fertiliæer Practice, several applications during the lOgrowing season.
**A total of 400 lbs. N in the form of UN-32 applied in several applications during the growing season ~o simulate Standard Fertilizer Practice.
All of the test corn plantings reported in these examples, where compared, were made within one week of each othPr if not essentially simultaneously.
Corn grown in plots Eertilized by method (2), broad-casting, then plowing in, looked green and robustly healthy. Corn grown in plots fertilized by broadcasting only, methods (1~ and (3), had yellow as well as green foliage, but was greener than corn fertilized by method (4), shanking in post-planting, which looked yellow.
In an effort to appro~imate yields wh~ch would not be available until later in the year, the ear counts in the same samples were retaken with the following adjustments: full ears recorded as 1, small ears as 1/2, and nubbins as 0~ This count has been recorded in Table IV as effective ear counts.
Table V
Corn Trials - Effect of~Application Method Effective Average Effective Nitrogen Level Melamine/ Application Number of Number of Number of Ears (lbs.facre) Urea Technique Ears/lQ0~** Plants/100 ft. per Plant 140-150 75/25 ~1) 109.5 109 1,0 140-150 75/25 (2) 118 126 0.94***
140-150 75/25 (3) 120.5 115 1.05 150 80/20 (4~ 60 134 0.45 0 (Control) - 40.5 95 0.43 400 UN-32 (1) 124.5 128 0.97 4Q0* * 145.5 159 0.92 *Standard Fertilizer Practice, several applications during the growing season.
**Full ears recorded as 1, small ears as 1/2, and nubbins as 0.
***Ear sizes were al80 of interest:
at 150 lbs. N, applled as a 75/25 melamine/urea prill: 5-1/2 - 6 cm. diam.
SFP : 4-1/2 - 5 cm. diam.
~7~
In a further evaluation, corn plants were harvested and welghed, an ear count was taken, and ear weights were recorded, from two test areas. The first area was fertilized with 75/25 melamine/urea agglomerates by broadcasting the agglomerates, then discing them in. The second area was fertilized according to local standard fertilizer prac~ice at 400 lbs. N~acre. Standard ferti-lizer practice calls for the application of a total of 350 lbs. to 400 lbs. N per year per acre. This is accomplished by three separate steps. First, an early application is made of 200 lbs.
~/acre as anhydrous ammonia. Second, 400 lbs./acre of 16-20-0 i5 applied (based on monoammonium phosphate). Third, UN-32, com-prising urea and ammonium nitrate, is applied through the irri-gation sprinkler system. The results are summari~ed in Table V
below. All samples taken were pre-dent.
Other aspects of the invention disclosed herein have been claimed in applications 411,587 and 411,595 filed simultaneously herewith.
Table VI
Pre-dent Evaluat~on of Corn Response Ratio of Ear Sample Selection Plants Ears Weight to Fertllization No. Technique Number Weight Number Weight Plant Welght Melamine/urea 75/25 1 Random 1/ 10 39 lbs. 20 18.5 lbs 0.475 Agglomerates, at 2 Random 1/ 10 35.5 20 16 0~45 150 lbs. Nfacre, 3 all taken 58 122 59 47.5 0.39 broadcast and rom a 50 ft.
disced row 75/25 Agglomerates9 4 all taken 69 122 73 49.5 0.41 ~
at 235 lbs. N/acre, from a 50 ft. ~ I
broadcast and disced row o~
75/25 Agglomerates, 5 all taken 64 134 67 47.5 0.35 at 150 lbs. N/acre, from a 50 ft. C~
flown on row Standard Fertilizer 1 Random 1/ 10 41 20 14 0.34Practlce, 350 to 400 2 Random L/ 10 41 20 16.5 0.40 lbs.N/acre 3 all taken 79 142 77 47 0.33 from a 50 ft.
row 1/ In the random selection process, large plants have 2 ears each were taken from the ends of rows in open spots where there was a m1n~nm of competition from other corn plants.
FERTILIZER COMPOSITIONS, PROCESSES OF MAKING THEM
AND PROCESSES OF USING THEM
BACKGROUND OF THE INVENTION
This inventiDn relates to a new fertilizer product in composite granular form, to a process for making it, and to a process for using ie . More particularly, the invention relates to a granular fertilizer product in which the granules have strength, sLzes, and weights suitable for mechanical dispensing and application to and into the soil. These new fertilizer granules provide a novel combination of fine particles: a particulate nitrogen source such as melamine together with a binder such as urea suitable for binding the particulate nitrogen source into granular form.
~ mmonia, am~onium nitrate and urea are among the most commonly used sources of nitrogen but all of these nitrogen fertili7er materials are readily soluble in water. They are therefore sub~ect to leaching, and their use results in a rapid release of their nitrogen. Since this necessitates repeated applications for sustained growth, Dr one application with higher leaching losses, there have been many developments relating to slow rel~ase nitrogen fertilizer materials. Generally such materials sacrifice nitrogen content for some degree of control over nitrogen availability.
M~l~m; ne and its hydrolysis products, -1~nP~ am~elide, and cyanuric acid, have been considered as potential sources of nitrogen for incorporation in fertilizer compositions or for utilization as nitrogen sources per se. Melamine has a nitrogen content of 66.6~. If it could be used as a fertilizer material, it would provide a good deal of nitrogen per unit weight applied.
However, at present it is more sY~pensive than urea. ~oreoverr commercially produced ~ mlne is available only as a fine crystalline powder. It is manufactured in the form of very fine crystals because small size particles are required for the present commercial end markets for r~l~mine, such as, for e~ample, the 7~
production of melamine-formaldehyde resins and the production of fire retardant paints.
A typical screen analysis for one comnercially available melamine, conducted with United States Standard Sieve screens, is as follows:
Percent Screen Analysis Retained 40 Mesh 0-0.1 40-50 Mesh 0-0.1 50-60 Mesh 0-0.3 60-80 Mesh 0.5-5.0 80--100 Mesh 1.0-5,0 100-200 Mesh 13-30 200-325 Mesh 13-30 Thru 325 Mesh 40-60 The commercially-produced small melamine crystals are desired by the resin producers because the small crystals dissolve more readily, and any larger particles, if present, would tend to require a longer processing time; therefore, the larger particles are less desirable. In the fire retardant paint market, the melamine crystals are dispersed in the paint, where the currently used fine particle sizes produce a smoother texture in the dried paint than would larger particles.
The fine particle sizes of the commercially available melamine products make melamine a product that is not very attractive for agricultural applications. Moreover, the fine particle sizes of commercial melamine as currently produced, make it impractical to use a fertilizer material. The fine particles, if applied to the surface of the ground~ would be blown away by even milt winds. If applied by air, as from an airplane or helicopter, drifting wou~d be a serious problem ~nd would cause uneven application. If applied through mechanical applicators, the fine particles would tend to form bridges and thus would plug transfer and dispensing lines. These difficultie~ in handling the 7~0 commercially available melamine solids would make any large scale agricultural application impractical.
SUMMARY OF THE INVENTION
In one of its aspects, this invention resides in a fertili~er product in granule form. The fertilizer granules have strength, sizes, and weights that are suitable for dispensing mech~nic~lly for application to and into the soil. The preferred size range is from about 1 millimeter to about 10 millimoters, and the most preferred size range is from 3 ~m. to 5 mm.
These fertilizer granules comprise a particulate nitrogen source and a binder. The nitrogen source is characterized by fine particle sizes not above about 10 mesh, by poor solubility in pH 7 water at 20C, and by slow conversion in the soil to a form in which it is useful to plant life growing in the soil. The nitrogen source is selected from the group of materials consisting of melamine, ammeline, ammelide, cyanuric acid, mixtures thereof, their inorganic salts, their organic salts and mixtures thereof.
The binder is present in an amount at least sufficient to bind together the fine crystals or powder particles of the nitrogen source, to form granules having the desired strength. It is preferably a readily soluble material that, after distribution of the granules in the soil, releases the nitrogen source particles to permit the action of water and microorganisms on the particles.
The binder is selected to be compatible ~ith the soil, and any residue of the binder should be either inert, biodegradable, soil condltioning or have plant nutrient value.
The binder is selected from the group of materials consisting of urea, ammon~um sulfate, potassium sulfate, ammonium nltrate, ammonium phosphata, potassium nitrate, potassium chioride, ammonium chloride, potassium dihydrogen phosphate, lignin sulfonate, urea formaldehyde resin, -l~m~nP formaldehyde resin, starch, latex and mixtures thereof.
In a preferred embodiment the granules comprise up to 80 parts by weight of the particulate nitrogen source and at least 20 parts by weight binder.
In a more preferred embodiment the granules comprise from 60 to 80 parts by weight melamine and from 20 to 40 parts by weight urea. In another preferred embodiment the granules comprise from 67 eO 80 parts by weight melamine and from 20 to 33 parts urea. In a most preferred embodiment the granules comprise about 67 parts by weight melamine and about 33 parts by weight urea.
In another aspect this invention resides in a granule prepared by a process having an annealing step to provide enhanced strength to the granule and adapting them for use as a source of nitrogen for fertilizing applications. This process involves mixing a particulate nitrogen source selected from the group of materials listed above with an effective amount of a binder suitable for binding the nitrogen source particles into granules having sizes and weights suitable for mechanical application. The mixture is then contacted with a spray of water or an aqueous solution of the binder. The moistened mixture is agglomerated, dried and annealed. In a preferred embodiment the process requires a dryin~ temperature of less than g30C and an ~nnP~ temperature between 135C and 149C. In a most preferred embodiment this granule is prepared from a mi~ture of from 50 to 80 parts by welght mPl~m~ne and from 50 to 20 parts by weight urea.
In another aspect of thls invention is a fertilizer in prill form. This prill is prepared by mixing an effective amount o~ a molten binder selected from the group of bi~der materials listed above with fine powder particles of a particulate nitrogen source selected from the group listed above. Drops of this mixture are then chilled to form prills. In a preferred embodiment this prill comprises from 40 ~to 65 parts by weight melamine as the particulate nitrogen source and from 35 to 60 parts by weight urea binder. In another preferred embodiment this prill comprises 50 to 60 parts by weight melamine and 40 to 50 parts by weight urea.
In another embodlment this invent~lon involves a process of preparing a fertilizer product in granular for~ adapted ~or use as a source of nitrogen for fertilizlng applications. This process involves mixing a particulate nitrogen source selected from the group listed above and an effective amount of a binder selected from the group listed above. The process involves contacting the mixture with a spray of water or an aqueous solution of the binder, agglo~erating the moistened mixture to form agglo~era~es and drying the agglomerates. The agglomerates are screened to produce product agglomerates havi~g sizes in th~ range of 1 milli~eter to 10 milli~eters, preferably. Over-sized particles can be crushed to size, and fines can be recycled.
In another preferred embodiment the process requires mixing from 50 to 80 parts by weight melamine with from 50 to 20 parts by weight urea binder. In a most preferred embodiment this process involves mixing about 67 parts by weight melamine with about 33 parts by weight urea.
In another embodiment this invention involves a process for preparing a granular agglomerate adapted for use as a source of nitrogen for fertilizing applications which involves an annealing step following and in addition to the mixing, contacting, agglomerating and drying steps of the process descrlbed above. In a preferred embodiment this invention involves drying the agglomerates at a temperature less than 93~C and annealing the dried agglomerates at a temperature between 135C and 149C. In another preferred embodiment this process comprises mixing from 50 to 80 parts by weight ~l~ne and 50 to 20 parts by weight urea.
As a rule, crush strengths of 1000 grams or greater are attained where the annealing step of heating to 135C to 149C ie carried out on the granules made from melamine and urea.
In another aspect this invention is a process of fer~
tili~ing crops comprising dispensing to the soil a granular product comprising a particulate nitrogen source selected from the group listed above and an effective amount of a b;nder selected from the --S
r. ~
group of binders listed above. In a preferred embodiment this process involves dispensing to the soil a granular product comprising up to 80 parts by weight of the particulate nitrogen source and at lease 20 parts by weight binder. In a most preferred embodiment this process involves dispensing a granular product comprising up to ~0 parts by weight melamine and at least 20 parts by weight urea.
In another aspect this invention is a process of fer-tilizing crops which involves dispensing to the soil a granular product having strength, size and weight suitable for mechanical dispensing and application formed by mixing an effective amount of a binder selected fro~ the group of binders listed above and a particulate nitrogen source selected ~rom the group of nitrogen sources listed above. After the mixing step the process involves contacting the mixture with a spray of water or an aqueous solution of binder, agglomerating the moistened mixture to for~
agglomerates, drying the agglomerates and annealing the dried agglomerates. In a preferred embodiment this process comprises mixing melamine as the particulate nitrogen source with a urea binder. In another preferred embodiment this process involves fertilizing a crop of corn, potatoes or rice.
In these processes of fertilizing crops, the total rate of application is such as to insert enough total long term er-tilizer nitrogen for an entire growing season. A primary ad-vantage of this process, and of the use of the composite granular fertilizer prepared in accordance with the invention, is that the rate of application of the fe~tilizer generally is less ~han one-half of that needed to achieve comparable results when ammonium sulfate is employed as the sole source of nitrogen and is applied as a solution through an irrigation sprinkler system.
In another aspect this lnvention is a process of fur-nishing a slow release source of fertilizer nitrogen to field soil as a nutrient source for a crop by inserting and distributing in the soil in the root ZQne in particulate form a fertilizer nitrogen source that ls characterized by poo~ solubility in pH 7 water at 20C. This slow release nitrogen source may be melamine, ~l~nP~
a~melide, cyanuric acid, their organic or inorganic salts or mixtures thereof. After applying the solid form of the nitrogen source on the surface of the soil a portion of the soll is turned over to insert and distribute the fertilizer at the desired depth range throughout the soil.
In another aspect this invention is a process of applying the slow release nitrogen source described above in tlle form of a slurry of solids suspended in an effective amount of a liquid vehicle for the nitrogen source that permits application of the slow release fertili~er particles to and their distribution in the soil.
DEFINITIONS:
The term "poorly water soluble" refers to materials that dissolve in water at 20~, pH7, to the extent of 5 grams per 100 grams, or less; that is, materials that form solutions of 5% or less concentration. The term l'poor solubility" in pH 7 water at 20C has the same meaning.
The term "readily water soluble" refers to materials that dissolve ln water at 20C, pH 7, to the extent of 20 grams per 100 grams or more, that is, materials that form solutions o~ 20% or greater concentration.
Based on available information, the solubilities in water at 20C, pH 7, for several materials useful in connection with this invention, in grams per 100 grams are:
Table I
Solubility Data Material ~ ~
30r~ m;nf~O.50 ne 0.008 ammelideless than 0.008 cyanuric acid 0.27 melamine nitrate 0. 85 ammonium nitrate 192 ammonium sulfate 75.4 7~
diammonium phosphate 131 (at 15) potassium acid sulfate 51.4 potassium sulfate 11.1 urea 119.3 (at 25C) DETAILED DESCRIPTION OF THE INVENTION
Fertiliæer products in accordance with the present in-vention are in granular form, with sizes in the range from about 1 mm. to 10 mm., preferably 3 mm~ to 5 mm. They are made up to have good drillability, a desirable apparent specific gravity, and to be substantially free from dusting. The granules are also made to be suitable for mechanical d~spensing and application to and into the soil using modern toolsO
Granular fertilizer products made in accordance with pre-ferred embodiments of the invention may be in the form of agglomer-ates or prills. The agglomerates may be made by any conventional technique for agglomerating fertilizer products, utilizing the poorly or slightly soluble fertilizer nitrogen sourcés of the present invention, followed by an annealing treatment to provide sufficient crush strength. Thus, the poorly or slightly soluble nitrogen source in an agolomerate is sPlected from the group consisting of melamine, ammeline, ammlelide, cyanuric acid, mixtures thereof, their inorganic salts, their organic salts, and mixtures thereof. These salts are preferably selected from the group consisting of the hydrochloride, hydroiodide, metaphosphate, nitrate, orthophosphate, orthophosphate dihydrate, polyphosphate, potassium dihydrogen phosphate, bisulfate, and sulfite, and, as well, the acetate, cyanurate, chloroacetate, formate, benzoate, fumarate, lactate, maleate, and phthala~e, and mixtures thereof.
These materials are characterized by poor or slight solubility in pH 7 water at 20C, and by slow conversion in the soil to a form in which the nitrogen is useful to plant life growin~ in the soil~
These nitrogen source materials, as ordinarily available commercially or as prepared, are in the form of very fine particles. In the case of -l~mine, for example, the co~mercially ~a7~
~vailable product typically has crystalline particles that are smaller in size than 10 mesh, U.S. Standard Sleve si~e, and generally, mostly smaller than 40 mesh. These very fine, powdery nitrogen source materials are agglomerated through the use of a binder. Generally the binder forms at least 1~ by weight of the powdery particles, preferably at least 2% by weigh~ of ~he powdery particles, and more preferably, at least 5~ by weight of the powdery particles. The blnder may be selected from a broad spectrum of materials, but preferably is selected to be compatible with the soil so that it and any residue thereof i5 either inert, biodegradab]e, soil-conditioning, or has some plant nutrient value.
The binder that is used should be sufficiently strong, upon hardening or curing, to impart to the granular agglomerates a crush strength of at least 454 grams, as determined by tests on ten agglomerates randomly selected, with sizes in the range from 3 mm.
to 4 mm., the results being averaged. Preferably, however, the crush strength is at least S80 grams, and more preferably, 908 grams or higher. A crush strength of about 45~ grams is comparable to conventional, commercial prilled urea and is adequate strength for use in most forms of commercial application, including broad cast devices, spreaders, planter shank applicators,`and for dis-pensing from airplanes and helicopters.
Among the preferred binders are those selected from the group consisting of lignin sulfonate and its salts, starch, urea, urea-formaldehyde resins, mPlAmlne-formaldehyde resins, and latices of synthetic polymeric materials. Those binders are most preerred that have plant nutrient value, as do urea, urea-for~aldehyde and melamine-formaldehyde resins.
In one preferred a~glomeration technique, the mpl~m~ne powder is combined with from 5% to 25~ by weight of powdered urea to for~ a blend. This blend is then sprayed with water or with a solution of urea, in an agglomerating de~lce such as on a rotating disc or in a rotating drum. In the case of a binder solution, the particles are coated. In the case of a water spray, the urea _g_ either goes into solution or becomes moistened and tacky, and in either state, coats the powdery melamine particles sufficiently to cause agglomeration to occur. ~he agglomerates are dried and cooled, to form hard composites having sizes pr-lmarily in the rante from about 1 mm. to about 10 mm., and preferably 3 mm. to 5 mm.
These composites have good crush strength and are substantially free from dusting.
Any of the conventional agglomerating techniques can be used. Thus, all of the binder can be applied in solution. Whe~
the binder is a material such as lignin sulfonate, urea-formaldehyde resin, or melamine-formaldehyde resin, application in the form of a solution is usually most convenient. The binder might also be a material such as a phenolic resin, applied from a solution, but such a material, while having exrellent characteris-tics as a binder, has no nutrient value to contribute and is there-fore less desirable. The same considerations apply to synthetic polymer latices.
The fertilizer particles of the invention may also be made in the form of prills. In the prilling operation, melamine powder is added to a molten binder material, preferably urea, to form a slurry of the melamine powder particles in the molten urea.
Droplets of this molten slurry are solidified by dropping them through a prillin~ tower, in the conveneional fashion. While urea is the preferred material for use in preparing prllls, because of its nitrogen content and ready solubility in water, and also because ~ mine is somewhat soluble in molten urea, other material such as sulfur could also be used, and mix~ures of materials could be used. In forming urea-bound prills, it is preferred that the prill product contain at least 33% by weight of urea. When less urea is present, it is difficult to prepare a flowable slurry. The urea content of the prill may be as high as 90~, so that the melamine content may be in the range from 10% to 67~ by weight of the prills. Preferably, the urea content is from 35% to 60% by ~7~
weight of the prills, and more preferably~ from 40~ to 50% by weight.
Whlle preferred granular products are produced by agglomera~ion and prilling, satisfactory products can be produced by other techniques, including extruding techniques, pressing and granulating, and bricquetting. For example~ ~J~m;ne powder, or a powdered melamine salt, or the like, can be combined with a urea formaldehyde resin in powder form to form a mi~ture. The mixture can be pressed at an elevated temperature to cure the resin, and the resulting product can be granulated to form particles of the desired size, or the pressed, cured mass can be converted to flake for~. Screening and recycling can be used as necessary to develop ~ranules of the deslred sizes.
Readily soluble binders such as urea and salts such as ammonium nitrate permit rapid disintegration of the binder of the Eertilizer granules in the soil, with release of the fine melamine or other fine particles. This may be desirable where the composite contains not only melamine but also a readily soluble, fast release r.itrogen fertilizer material. Where slow release is desired, then ordinarily one of the binders is employed that loses binding power more slowly in the soil, such as, for e~ample, a urea-formaldehyde resin or a -lAm;ne-formaldehyde resin.
Urea is a preferred binder for agglomerates, or for making prills, because it not only permits the production of fer-tilizer granules of sufficient size, strength, and weight, for convenient applicationl but in addition, the urea is readily soluble and adds valuable fast release nutrient material to the soil. When used with a powdered nitrogen source characterized by poor or slightly solubility and slow conversion in ehe soil to a useful form, the urea dissolves rapidly and releases the fine particles of the poorly soluble nitrogen source into the soil, for slow dissolution or biodegradation.
~ hen an agglomerate is prepared fro~ powdered r~l~m~ne and a readily water soluble binder such as urea, preferred pro-~,Jb~
portions in the dried granular product obtained are from 60% to 85 by weight of melamine and from 40~ to 15~ by weight of urea~ or more preferably, from 67% to 80% by weight of melamine and from 33%
to 20% by weight of urea. The most preferred granule comprises about 67 parts by weight melamine and about 33 parts by weight urea.
I~en an agglomerate is produced using an insoluble or only slightly soluble binder such as starch, a derivatized starch9 or a modified starch, lignin sulfonate, urea-formaldehyde, or -l~m~nP-formaldehyde, or one of the non-m1trient materials such as a phenolic resin, or a synthetic polymer in the form of a latex, a very slow release of nitrogen from the-melamine particles (or particles of other poorly soluble nitrogen source) is obtained.
For the production of an agglomerate permitting a single application per growing season, fast release nitrogen fertilizer I materials, generally an ammonium salt or urea, are advan~ageously used as the binder of the agglomerate. Examples of such salt-type binder materials are ammonium sulfate, potassium sulfate, ammonium phosphate, diammonium phosphate, the potassium phosphates, ammonium nitrate, potassium nitrate, potassium chloride, and ammonium chloride. When used as a binder material in the formation of an agglomerated composite, the proportion of such salt-type binder material may be from 15~ to 40% by weight of the agglomera~e, and preferably is from 20% to 33% by weight of the agglomerate.
In addition, other materials may be incorporated in a granular fertilizer product prepared in accordance with the in-vention. Such materials may be micronutrients such as zinc, magnesium, iron and boron.
One of the advantages of the use of granular fertilizer compositions prepared in accordance with the present invention is that the rate of application may be much lower in terms of nitrogen applied per acre than i9 true with standard fertilizer practice.
Because less of the active material is actually needed, it may be desirable, to facilitate application, in some cases9 to incorporate an inert filler. Any of the conventional filler materials may be e~ployed, such as, for example, gypsum, clay9 sand, ground se~
shells, ground dolomite, and ground limestonP.
Another important advantage of the use of granular fertilizer products in accordance with the present invention is that, because of the slow release characteristics, lt is possible to employ only a single application per growing season. In addition, after the initial application, in the case of L.el~mi~e based fertilizer products in particular, the release of nitrogen values into the soil appears to continue over two growing seasons.
Consequently, in the second and subsequent gro~ing seasons, even lower rates of application may be employed for given results, than may be used for the initial application.
Another aspect of the invention ls the unexpected and surprising finding that furnishing a majority or all of the nitrogen fertilizer requirements by a nitrogen fertilizer source in accordance with the present invention apparently leads to a more effective production of agricultural productive units per unit weight of nitrogen ~pplied, and per unit of growing area. A~
agricultural productive unit is a seed, fruit, flower, vegetable, vegetable fiber, tuber, or the like. In addition, the practice of the invention apparently leads to overall yields of plant units comparable to those obtained when following conventional, standard fertilizer praceice, with its requirement for the use of much higher nitrogen fertilizer application levels.
In broad terms, this invention may be considered, in one example, as a process for increasing the effectiveness of standard readily soluble, fast release nitrogenous fertilizers in generating productive units in agricultural crops by supplementing their action ~ith the use of a slow release, poorly or slightly soluble fertilizer nitrogen source. Thus, a combination of fro~ about 10%
to about 50% of the nitrogen in a standard readily water soluble, fast release nitrogenous fertilizer may be combined advantageously with from about 50~ to 90~ of poorly soluble materials recited above.
The agricultural crops expected to respond to treatment in accordance with the invention include substantially all crops, but particularly those where fruit is the harvested unit rather than the entire plant. Such crops include food grains, feed grains, legumes, fibers, root crops, citrus, tubers, oil bearing units including nuts, fruits and seeds, commercial vegetables, commercial melons, ~ree fruits, vine fruits, bush fruits and flowers. Exemplary food grains include wheat, rye, and rice Feed grain crops include field corn, oats, barley and sorghum. Legumes include soybeans, peanuts, beans and peas. Fiber crops include cotton, hemp and jute. Root crops include sweet potatoes and sugar beets. Citrus crops include oranges, tangerines, grapefruit~
lemons and limes. Tuber crops include potatoes. Oil crops include flax, safflower, sunflower, and castor bean. Commercial vegetable crops include lima beans, snap beans, beets, carrots, sweet corn, cucumbers, onions, green peas~ and tomatoes. Commercial melon crops include cantaloupes, honeydews and watermelon. Tree fruit crops include apples 7 peaches, pears, cherries, and plums. ~ine fruits include grapes. Bush fruits include the many different kinds of ber}ies, especially raspberries and blueberries. Tree nut crops include almonds, filberts, pecans and walnuts. These are intended to be exemplary only.
The invention will be better understood by reference to the following examples. Throughout this application and in these examples, all references to parts and percentages are by weight, and all references to temperatures are in degrees Celsius, unless expressly stated otherwise.
Examples of the Formation of Granules that are Useful in the Process of the Invention In all of the following examples, the melamine used was the commercially available product of ~ ml~e Chemicals, IncO, Donaldsonville, Louisiana. It was a fine white crystalline powder 37~L0 having a screen analysis substantially as reported above for co~mercially available melamine. It was about 99.9% pure, with specifications of a r~1ml1m moisture content of 0.1~ mllm ash of 0.01%, and a density of about 1.57 g/ml.
As is pointed out in some of the following examples, crush strengths of 454 grams or greater are preferred. More preferably crush strengths of 1362 grams or more are developed, to facilitate application. Also, the bulk density of the granules should be 40 lbs./ft3 or more. The preferred combination of bulk density, crush strength, and particle size makes }or flexibility in and ease of application. Usually crush strengths of 1000 grams or greater are attained when the annealing step of heating to 135C to 149C is carried out on the melamine urea granules.
EXAMPLE I
M~l~m;ne Agglomerates Using a Urea Binder Three batches of composite granules were made up, each containing different amounts of urea and melamine, with urea serving as the binder. These batches of agglomerated granules were made in a pan agglomerator of 9" diameter. The urea was first ground, and then blended with the melamine powder to form a homo geneous mixture. The powder mixture was fed to the pan agglomerator and sprayed with a nearly saturated solution of ure~
and water, The solution added about 7% urea to the dried agglo-merate. The remainder of the urea content was derived from the urea powder in the urea-melamine powder mixture.
Example II
Annealed M~lAmine Granules A batch of granules was prepared using 67 parts of melamine crystals and 33 parts urea. The granules were made on an 18 inch disc pelletizer. The urea was first ground, then blended with the ~ mine to form a homogeneous mixture. This mixture was fed to the pelletizer and sprayed with water. T~e granules were dried at 200F. (94C) for about 20 minutes and then were subjected to a further step of heating in a laboratory oven to 149C for 3 ~7~
minutes. After cooling, the crush strength and rate of breaking apart in water were measured. These values are reported in Table I
below.
Table I
Crush Strength Time to Disintegration (grams) in Water Example 1 600 immediate Dried Granules Example II 2400 20 to 30 seconds Annealed Granules This Example illustrates the relationship between time and temperature in the annealing step.
Example III
Annealed MPl~mine Granules Melamine granules prepared according to E~ample II were heated in separate batches at 104C, 149C, and 172C for varying times. A standard laboratory oven was used. After cooling, the crush strength was measured. The results appear in Table II. The r~;mllm crush strength at 172C appears at 6 minutes heating~ The r~imllm crush strength appears at 149C at 11 minutes heating.
Shorter drying times and annealing times will be possible in pro-duction when forced air dryers or ovens will be used in place of the laboratory oven used in these examples.
Table II
Oven Temperature Minutes Crush Strength C Heating (grams~
\
~37~
lS 1530 145~
Example IV
Melamine Agglomerated with Urea Powder; Water Spray One batch of agglomerated granules was prepared in a pa~
agglomerator as in Example 1, except that all of the urea was added as a powder, and the spray applied at the pan consisted only of water. The resulting composites contained 80% melamine and 20%
urea, and after screening to 3-4 mm., were found to have a crush strength of 953 g. using the same testing technique as in Example I.
Example V
Use of Other Binders for Agglomerating Melamine Granular agglomerates were prepared wlth a 16 inch pan agglomerator using r~lAm~ne with several different bindersO In each case, the binder, in liquid form, was sprayed on the melamine.
After drying, crush strength was deternined as in Example I. The results are reported in Table III, below.
TABLE III
Crush Strengths ObserYed Melamine Agglomerated with Different Binders Crush Strength, grams of 3-4 mm.
Binder Agglomerates Calcium lignin sulfonate1 908 7~
UCAR 368 latex 681 Melamine-formaldehyde resinl 1544 Urea-formaldehyde resin 454 Diammonium phosphate {DAP) 91 Ammonium nitrate2 150 1Applied at 30%-50% solids. The dried agglomera~es were about 5Z binder.
Substantially saturated solutions used. The dried agglo-merates were approximately 93% melamine, 7% salt.
Example VI
Melamine Agglomerated with other Fertilizer Materials Melamine, ammonium phosphate, and potassium chloride were blended together in a 70:15:15 weight ratio. The mixture was fed to a 16 inch pan agglomerator and sprayed with a 30% solids lignin sulfonate solution. The dried, screened granules had a crush strength of 1000 grams in the 3-4 mm. size range, and a binder content of 3Z.
- Example VII
Melamine in Matrix of Solidified Urea Binder Melamine and urea powder werP blended in a 63-37 ratio.
The blend was heated until a molten slurry was obtained. The slurry was then poured onto a cooling slab so as to form both a thin film and a thick film. After cooling the thin film was broken into flakes.
The thick film3 of about 4 mm. thickness, was broken into granules. The crush strength of the 3-4 mm. granules was ex-ception~lly high, at 2500 grams.
Example VIII
A Pressed ~Pl~m;~e-Urea Composite A melamine-urea blend was formed as in Example VII. This blend was then placed in a heated platen press at about 500 psi for 5 minutes, at 138C. The resulting hot composite9 in the form of a sheet about 4 mm. thick, was then removed from the press and ~18-~ ~ ~7~ ~ ~
allowed to cool. The cooled sheet was granulated, and 3 4 mm.
granules of the composite had a crush strength of 2500 grams.
Example IX
Melamine-Urea 60/40 Prills Melamine composite prills were prepared by heating 40 parts urea by weight with 60 parts ~ m;ne by weight. Heating was done in an aluminum can using electric heating tape. A slurry formed at 135C. Holes were then punched in the can bottom, allow-ing the slurry to drip. A plastic sheet spread on the ground caught the falling prills as they dropped from the fourth story level.
The largest prills did not cool before landing and smashed. However, the smaller pr~lls cooled and solidified, and were collected for strength testing. Fairly good strength results were achieved, although not measured. Crush strength would be e~pected to be similar to the granules of Example VII.
Example X
Melamine Agglomerated with a Late~ Binder 5% Union Carbide UCAR 368 Latex, 15% water, and 80%
melamine were combined into a flowabl~ slurry. A sheet of the slurry was formed and then dried. An extremely strong composite resulted which could be granulated. The dried material contained 3~ latex solids and 97% melamine. The crush strength of 3-4 mm~
granules was 2180 grams.
Example XI
Pressed Composite of ~elamine and Ure-Formaldehyde 25 grams of urea, 70 grams melamine, and 15 ml. of 27%
formaldehyde solution were mixed together and pressed at 149C and 500 psi to form a thick sheet. Crush strength of 3-4 mm. granules 3C ~as 680 grams.
Example XII
Melamine-Urea Agglomerates for Field Trials For field trials, 16,000 pounds of mPl~mine/urea com-posites were made using 4 foot diameter pan agglomerators.
Different composites were produced, at the melamine/urea ratios of 80/20, 75/25, and 67/33. Approximately 7% of the composites was provided by the urea added in the form of an aqueous binder solution, and the remaining urea was provided by powdered urea that was blended with the melamine powder prior to agglomeration.
In the foregoing examples, granular fertilizer products were prepared from commerciaLly available9 fine crystals of melamine. Similar granular fertilizer products can be prepared in substantially the same fashion from the hydrolysis products of melamine, i.e. ammeline, ammelide, and cyanuric acid, and from salts made from them and from m~l~m;ne~ Among the salts, the reaction product of nitric acid and melamine is a preferred material.
Example XIII
Corn Trials Using Melamine-Urea Agglomerates; Evaluation of Different Application Techniques Test plots totaling 40 acres of sandy to light loams and silts were treated with different amounts of melamine agglomerates to provide several different levels of applied nitrogen per acre.
MP1~mine-urea agglomerated composites were used, prepared according to Example I and having 67 parts melamine to 33 parts urea binder;
75 parts melamine to 25 parts urea binder; and 80 parts melamine to 20 parts urea binder. The composites were successfully applied using different techniques: 1) spreading with a Barber spreader; 2) spreading with a Barber spreader and plowing into the ground; 3) aerial application by airplane; 4) shanking into the ground during planting.
The results observed are summarized in Table IV below.
Table IV
Corn Trials - Effect of Application Method Number of Average ~umber Nitrogen Level Melamine/ Application Ears/100 of Ears (lbs./acre UreaTechnique Plants per Plant 140-150 75/25 (1) 155 1.55 140-150 75/25 (2) 147 1.47 1~0-150 75/25 (3) 155 1.55 150 80/20 (4) 153 1.53 0 (Control~ - 132 1.32 400 UN-32 ** 129 1.2g 400* * 145 1.45 *Standard Fertiliæer Practice, several applications during the lOgrowing season.
**A total of 400 lbs. N in the form of UN-32 applied in several applications during the growing season ~o simulate Standard Fertilizer Practice.
All of the test corn plantings reported in these examples, where compared, were made within one week of each othPr if not essentially simultaneously.
Corn grown in plots Eertilized by method (2), broad-casting, then plowing in, looked green and robustly healthy. Corn grown in plots fertilized by broadcasting only, methods (1~ and (3), had yellow as well as green foliage, but was greener than corn fertilized by method (4), shanking in post-planting, which looked yellow.
In an effort to appro~imate yields wh~ch would not be available until later in the year, the ear counts in the same samples were retaken with the following adjustments: full ears recorded as 1, small ears as 1/2, and nubbins as 0~ This count has been recorded in Table IV as effective ear counts.
Table V
Corn Trials - Effect of~Application Method Effective Average Effective Nitrogen Level Melamine/ Application Number of Number of Number of Ears (lbs.facre) Urea Technique Ears/lQ0~** Plants/100 ft. per Plant 140-150 75/25 ~1) 109.5 109 1,0 140-150 75/25 (2) 118 126 0.94***
140-150 75/25 (3) 120.5 115 1.05 150 80/20 (4~ 60 134 0.45 0 (Control) - 40.5 95 0.43 400 UN-32 (1) 124.5 128 0.97 4Q0* * 145.5 159 0.92 *Standard Fertilizer Practice, several applications during the growing season.
**Full ears recorded as 1, small ears as 1/2, and nubbins as 0.
***Ear sizes were al80 of interest:
at 150 lbs. N, applled as a 75/25 melamine/urea prill: 5-1/2 - 6 cm. diam.
SFP : 4-1/2 - 5 cm. diam.
~7~
In a further evaluation, corn plants were harvested and welghed, an ear count was taken, and ear weights were recorded, from two test areas. The first area was fertilized with 75/25 melamine/urea agglomerates by broadcasting the agglomerates, then discing them in. The second area was fertilized according to local standard fertilizer prac~ice at 400 lbs. N~acre. Standard ferti-lizer practice calls for the application of a total of 350 lbs. to 400 lbs. N per year per acre. This is accomplished by three separate steps. First, an early application is made of 200 lbs.
~/acre as anhydrous ammonia. Second, 400 lbs./acre of 16-20-0 i5 applied (based on monoammonium phosphate). Third, UN-32, com-prising urea and ammonium nitrate, is applied through the irri-gation sprinkler system. The results are summari~ed in Table V
below. All samples taken were pre-dent.
Other aspects of the invention disclosed herein have been claimed in applications 411,587 and 411,595 filed simultaneously herewith.
Table VI
Pre-dent Evaluat~on of Corn Response Ratio of Ear Sample Selection Plants Ears Weight to Fertllization No. Technique Number Weight Number Weight Plant Welght Melamine/urea 75/25 1 Random 1/ 10 39 lbs. 20 18.5 lbs 0.475 Agglomerates, at 2 Random 1/ 10 35.5 20 16 0~45 150 lbs. Nfacre, 3 all taken 58 122 59 47.5 0.39 broadcast and rom a 50 ft.
disced row 75/25 Agglomerates9 4 all taken 69 122 73 49.5 0.41 ~
at 235 lbs. N/acre, from a 50 ft. ~ I
broadcast and disced row o~
75/25 Agglomerates, 5 all taken 64 134 67 47.5 0.35 at 150 lbs. N/acre, from a 50 ft. C~
flown on row Standard Fertilizer 1 Random 1/ 10 41 20 14 0.34Practlce, 350 to 400 2 Random L/ 10 41 20 16.5 0.40 lbs.N/acre 3 all taken 79 142 77 47 0.33 from a 50 ft.
row 1/ In the random selection process, large plants have 2 ears each were taken from the ends of rows in open spots where there was a m1n~nm of competition from other corn plants.
Claims (15)
1. A process for furnishing a source of fertilizer nitrogen to field soil as a nutrient source for a crop by placing a granular fertilizer product, that in the soil is a source of nitrogen fertilizer values, on or in the soil at depths down to about 14 inches, comprising applying to field soil granules of said product that are from 1 mm. to 10 mm in size, consisting of an amount from 10% to 67% by weight of said granular product of discrete particles of melamine having particle sizes not above 400 micrometers, and an effective amount of from 33% to 90% by weight of a urea binder that binds said discrete particles in a form that is granular and that, after distribution of the granules in the soil, permits the action of water and microorganisms on said individual melamine particles, said granules having been formed by heating a mixture of said particles of melamine and said urea binder above the melting point of urea, then cooling, to solidify the urea, said granules being suitable in granule strength and weight for mechanical dispensing and for application to or into the soil, the average crush strength of a sample of said granules, selected to have sizes of 3 mm to 4 mm., being at least one pound per granule said melamine particles being characterized by slow conversion in the soil to a form in which the nitrogen is useful to plant life growing in the soil.
2. The process of claim 1 wherein said urea binder is soluble to the extent of 20 grams or more per 100 grams of Ph 7 water at 20°C, comprising applying the granules to the surface of the soil prior to planting, applying water to the granules and soil as through an irrigation sprinkler system, and then disrupting the soil as by discing, rototilling, or plowing, to distribute the applied material at the desired depths within the soil.
3. The process of claim 1 wherein said urea binder is soluble in water to the extent of 20 grams or more per 100 grams of Ph 7 water at 20°C, and wherein said binder, after distribution of the granules in the soil, can dissolve in soil moisture to release said melamine particles as discrete particles for the action of water and microorganisms thereon.
4. The process of claim 3, wherein said urea binder furnishes at least 25% of the total fertilizer nitrogen supplied by application of said granules.
5. The process of claim 1 comprising applying said granules to the soil by inserting and distributing them in said field soil, said granules being formed from at least 67% by weight of said discrete particles of melamine and not more than 33% by weight of said urea binder.
6. The process of claim 1 wherein the rate of application of said granules for a single growing season is such as to provide a quantity of nitrogen from said melamine amounting to from 10% to 75% of the standard fertilizer practice rate of application for the entire growing season, based on their respective nitrogen contents by weight, of a conventional, fast release nitrogen fertilizer material that is soluble to the extent of 20 grams or more per 100 grams of pH 7 water at 20 C.
7. A process for furnishing a source of fertilizer nitrogen to field soil as a nutrient source for a crop comprising:
applying on or in the soil at depths down to about 14 inches particles of a material selected from the group consisting of the mineral acid salts of melamine, melamin, and mixtures thereof, said particles being characterized by fine particle sizes not above about 400 micrometers, said particles being available in the soil after distribution therein in the form of discrete particles for the action of moisture and microorganisms on said discrete particles, said particles being further characterized by slow conversion in the soil to a form in which the nitrogen content thereof is useful to plant life growing in the soil, the rate of application of said fine particles for a single growing season being at a rate that is from 10% to 75% of the rate of application for the entire growing season, based on their respective nitrogen contents by weight, of a conventional fast release fertilizer material that is soluble to the extent of 20 grams or more per 100 grams of Ph 7 water at 20°C, the particles being applied in the form of granules that in the soil are a source of nitrogen fertilizer values and that consist of a mixture of melamine particles and an effective amount of a binder that binds the particles in granular form such that, after distribution of the granules in the soil, action of water and microorganisms on individual melamine particles is permitted.
applying on or in the soil at depths down to about 14 inches particles of a material selected from the group consisting of the mineral acid salts of melamine, melamin, and mixtures thereof, said particles being characterized by fine particle sizes not above about 400 micrometers, said particles being available in the soil after distribution therein in the form of discrete particles for the action of moisture and microorganisms on said discrete particles, said particles being further characterized by slow conversion in the soil to a form in which the nitrogen content thereof is useful to plant life growing in the soil, the rate of application of said fine particles for a single growing season being at a rate that is from 10% to 75% of the rate of application for the entire growing season, based on their respective nitrogen contents by weight, of a conventional fast release fertilizer material that is soluble to the extent of 20 grams or more per 100 grams of Ph 7 water at 20°C, the particles being applied in the form of granules that in the soil are a source of nitrogen fertilizer values and that consist of a mixture of melamine particles and an effective amount of a binder that binds the particles in granular form such that, after distribution of the granules in the soil, action of water and microorganisms on individual melamine particles is permitted.
8. The process of claim 7, comprising applying said particles in the form of granules that in the soil are a source of nitrogen fertilizer values, are from 1 mm. to 10 mm. in size, and that consist of a mixture comprising:
an amount from 10% to 90% by weight of said granules of a binder that is soluble in water to the extent of 20 grams or more per 100 grams of pH 7 water at 20°C and that binds said discrete particles in a form that is granular and that, after distribution of the granules in the soil, permits the action of moisture and microorganisms on said individual discrete particles, said granules being suitable in granule strength and weight for mechanical dispensing and for application to or into the soil, and the average crush strength of a sample of said granules, selected to have sizes of 3 mm. to 4 mm., being at least one pound per granule.
an amount from 10% to 90% by weight of said granules of a binder that is soluble in water to the extent of 20 grams or more per 100 grams of pH 7 water at 20°C and that binds said discrete particles in a form that is granular and that, after distribution of the granules in the soil, permits the action of moisture and microorganisms on said individual discrete particles, said granules being suitable in granule strength and weight for mechanical dispensing and for application to or into the soil, and the average crush strength of a sample of said granules, selected to have sizes of 3 mm. to 4 mm., being at least one pound per granule.
9. The process of claim 8 wherein said binder is urea and comprises at least 20% of said granules by weight.
10. The process of claim 8 wherein the binder is urea that has been solidified from the molten state.
11. The process of claim 8 wherein the binder for the granules is a material selected from the group consisting of ammonium sulfate, potassium sulfate, ammonium phosphate, diammonium phosphate, the potassium phosphates, ammonium nitrate, potassium nitrate, potassium chloride, ammonium chloride and mixtures thereof.
12. The process of claim 8 wherein said binder is solidified from the molten state.
13. The process of claim 9 wherein said granules are agglomerates, and said particles are melamine particles and comprise from 60% to 85% by weight of said mixture.
14. The process of claim 9 wherein said granules are prills and said particles are melamine and comprise from 10% to 67% by weight of said mixture.
15. The process fo claim 7, comprising applying said particles in the form of granules that in the soil are a source of nitrogen fertilizer values, that are from 1 mm. to 10 mm. in size, and that consist of a mixture comprising:
an amount not above 99% by weight of said granules of said discrete particles and an effective amount of at least 2% by weight of said granules of an insoluble resin binder that binds said discrete particles in a form that is granular, and that, after distribution of the granules in the soil, permits the action of moisture and microorganisms on said individual discrete particles, said granules being suitable in granule strength and weight for mechanical dispensing and for application to or into the soil and the average crush strength of a sample of said granules, selected to have sizes of 3 mm. to 4 mm., being at least one pound per granule.
an amount not above 99% by weight of said granules of said discrete particles and an effective amount of at least 2% by weight of said granules of an insoluble resin binder that binds said discrete particles in a form that is granular, and that, after distribution of the granules in the soil, permits the action of moisture and microorganisms on said individual discrete particles, said granules being suitable in granule strength and weight for mechanical dispensing and for application to or into the soil and the average crush strength of a sample of said granules, selected to have sizes of 3 mm. to 4 mm., being at least one pound per granule.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US30539481A | 1981-09-25 | 1981-09-25 | |
| US305,394 | 1981-09-25 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1197110A true CA1197110A (en) | 1985-11-26 |
Family
ID=23180610
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000411552A Expired CA1197110A (en) | 1981-09-25 | 1982-09-16 | Fertilizer compositions, processes of making them, and processes of using them |
Country Status (3)
| Country | Link |
|---|---|
| JP (1) | JPS5869795A (en) |
| CA (1) | CA1197110A (en) |
| PH (1) | PH20156A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA1237292A (en) * | 1983-07-28 | 1988-05-31 | G. Graham Allan | Sustained release compositions for biologically active materials |
| CA1265354A (en) * | 1984-11-15 | 1990-02-06 | G. Graham Allan | Liquid biologically active compositions |
| US9994799B2 (en) | 2012-09-13 | 2018-06-12 | Ecolab Usa Inc. | Hard surface cleaning compositions comprising phosphinosuccinic acid adducts and methods of use |
-
1982
- 1982-09-15 PH PH27880A patent/PH20156A/en unknown
- 1982-09-16 CA CA000411552A patent/CA1197110A/en not_active Expired
- 1982-09-24 JP JP57167450A patent/JPS5869795A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| PH20156A (en) | 1986-10-09 |
| JPS5869795A (en) | 1983-04-26 |
| JPS6112878B2 (en) | 1986-04-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4832728A (en) | Fertilizer compositions, processes of making them, and pocesses of using them | |
| US4560400A (en) | Fertilizer compositions, processes of making them and processes of using them | |
| EP1487761B1 (en) | Method for producing a particulate urea-formaldehyde polymer as slow release nitrogen fertilizer | |
| EP1323692B1 (en) | Microgranular fertiliser composition for sowing and transplanting | |
| CA2006751C (en) | Homogeneous granular nitrogen fertilizer | |
| JPS5934159B2 (en) | Granular fertilizer composition and method for producing the same | |
| US20090165515A1 (en) | Granular slow-release nitrogenous fertilizer | |
| US5139555A (en) | Fertilizer processes and compositions using s-triazines | |
| US5102440A (en) | Granular slow release fertilizer composition and process | |
| CA1197110A (en) | Fertilizer compositions, processes of making them, and processes of using them | |
| CA1188536A (en) | Fertilizer compositions, processes of making them, and processes of using them | |
| GB2112765A (en) | Fertilizers | |
| US4559075A (en) | Fertilizer processes and compositions using s-triazines | |
| US4554003A (en) | Fertilizer processes and compositions using s-triazines | |
| EP0135714A2 (en) | Sustained release compositions for biologically active materials | |
| BE894470A (en) | FERTILIZER COMPOSITIONS, METHODS OF MAKING SAME, AND METHODS OF USING SAME | |
| KR20010086703A (en) | Process for preparing effects-controlled fertilizer and the product therefrom | |
| CS259509B2 (en) | Fertilizer in granular form and method of its production |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |